Re: GEMDOS re-entrancy

[Juergen Lock <nox@jelal.north.de>]

Evan K. Langlois writes:

> ========================================================================
> Yes, that is it, indeed. But everybody sees the necessity to have such a
> TOSFS, but nobody develops it :(
> ========================================================================
> 
> Why not have TOSFS lock the system, but not other drivers?

 this is what would happen with the filesystem-multithreaded flag...
and you could still use the CPU when Rwabs called from GEMDOS goes to
sleep.

> ========================================================================
> But maybe it is good, that there is still no code around, so we could wait
> for the chicago fs and implement it then all-in-one...
> ========================================================================

 you people think too much peecee :)  i would be more intrested in what
the BSD 4.4 filesystem improvements are for example...

> ========================================================================
> That is what I suggested a long time ago, but as far as I know AHDI does
> not use it. It just sets it for every access, but never checks it before
> doing so :(
> ========================================================================
> 
> Don't we need a new disk driver anyway that won't block the system?  I thought
> that once we called AHDI, MiNt would loose control.  Someone said they had
> SCSI code.  I'd be in favor of hacking up a new driver.

 claus? :)
> 
> ========================================================================
> Well, yes and no. The floppy data transfer is done via DMA, the same DMA
> channel as the ACSI HD interface uses. So it will lock out that hard disk
> access. But on a TT, there should be a chance that there can be floppy
> transfer at the same time as SCSI transfer... provided that there is the
> software to support it.
> ========================================================================
> 
> That would be nice.  To be formatting a floppy, saving data to the SCSI
> drive, and still be able to do serial IO (Zmodem could save a block and
> read in another at once - who needs flow control?).  And you could be
> doing a ray-trace too :-)   I guess I'm just dreaming.  

 btw here is a reason why TT SCSI should not use flock, because that
would more or less block doing ACSI/floppy IO at the same time...
> 
> So, we replace AHDI with a real SCSI/ACSI driver and implement a new TOSFS.

 is tosfs really that important?  i mean who now needs it for more than
data exchange (floppies) and the boot filesystem?

> some other minor hacks (the SCSI device driver should handle
> putting processes on the wait queue and such).

 ACSI ofcourse too.

 cheers
	Juergen
-- 
J"urgen Lock / nox@jelal.north.de / UUCP: ..!uunet!unido!uniol!jelal!nox
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